Support structures, such as utility poles, are often used to suspend electrical lines, such as power distribution lines, above the ground. These support structures are generally located outdoors and may be of a variety of different configurations to suspend one or more lines. One problem with such lines, particularly with power distribution lines that transmit electrical power at high voltages, is that birds or other animals may land or climb onto the lines. Such contact of distribution lines by animals, particularly adjacent the support structure, may cause a short or electrical flash-over allowing current flow through the animal, which may cause a power outage or other problem with the power distribution system.
For example, it is known that birds from time to time perch on support structures such as utility poles. For certain birds, their wing span is great enough to contact two parallel lines or otherwise create an electrical flashover during takeoff or landing. In addition to harming the bird, such an electrical flashover can also cause a power outage or other problem with the power distribution system.
A solution that may reduce the likelihood of an electrical flashover due to animal incursion onto power distribution structures may be provided in U.S. Patent Application Publication No. 2016/0233010, which is incorporated by reference in its entirety as if fully set forth herein. For example, brief reference is made to FIG. 1, which is a top, rear perspective view of a protective cover assembly as discussed therein.
With reference to FIGS. 1 and 2, a protective cover assembly 101 includes an insulator cover 100 and a retaining pin 140. The insulator cover 100 includes a cover body 110, a mounting bracket 130, fasteners 139, and a plurality (as shown, four) connector members or clips 150.
The cover body 110 has a longitudinal axis L-L. The cover body 110 includes a central or main body or shroud section 112 and a pair of opposed, laterally extending, generally inverted U-shaped body extensions or legs 120. Generally, the main body section 110 provides coverage for the electrically conductive components of an insulator and the overlying portion of a conductor 20, and the legs 120 provide coverage for more extant opposed portions of the conductor. The insulator cover 100 is adapted to receive an insulator and portions of the conductor such that at least a portion of the conductor 20 generally extends along a lengthwise conductor axis C-C.
The main body section 112 defines a central insulator cavity 114A to receive the insulator, a bottom opening 114B communicating and contiguous with the cavity 114A, and a rear end slot communicating and contiguous with the cavity 114A and the bottom opening 114B. The main body section 112 further includes a front end wall opposite the rear end slot, and a top wall opposite the bottom opening 114B.
The legs 120 each define a leg channel 122A to receive the conductor. An elongate bottom opening 122B communicates and is contiguous with each leg channel 122A. Each channel 122A and its bottom opening 122B terminate at the insulator cavity 114A and the main body bottom opening 114B at one end, and at a distal end opening 122C at the other end.
While protective cover assemblies may reduce electrical flashovers due to wildlife, such as birds, when arcs between conductors do occur, significant conductor damage may occur when an arc is present at the same point on a conductor for a prolonged period of time. For example, reference is now made to FIG. 2, which is a schematic side view of an arc travelling between two conductors that include protective covers. First and second conductors 20A and 20B are covered using insulator covers 100A and 100B, respectively. The insulator covers 100A and 100B may include bottom openings 114B and/or 122B.
As illustrated, an electrical arc may occur between conductors 20A and 20B. Each of the lines 90, represents an arc location at a different time interval t0-t5. For example, the arc 90_0 may represent the arc location at the time the arc occurs t0. As the arc travels, at time t1 the arc location 90_1 may be at different points along both of the conductors 20A and 20B relative to the arc location 90_0. Continuing, as the arc travels, at time t2, the arc location 90_2 may be at still different points along both of the conductors 20A and 20B relative to the previous arc locations 90_0 and 90_1.
However, as the arc travels, at time t3, the arc location 90_3 may be at a different location on conductor 20A than at previous times t042, but may stay at generally the same location on conductor 20B as the location at time t2. The reason that the arc may travel along conductor 20A is that the insulator cover 100A includes bottom opening 114B and/or 122B. As such, the insulating cover does not interrupt the movement of the arc along conductor 20A. In contrast, since the insulator cover 100B is closed at the top and sides, the movement of the arc is significantly reduced and the arc location along conductor 20B is substantively unchanged between times t2 and t3. Similarly, at times t4 and t5, the arc locations 90_4 and 90_5 illustrate that the arc continues to move along conductor 20A, but stays at the same location on conductor 20B. The result is that the arc may be located at the same point along conductor 20B for a prolonged time period (t2-t5), which may result in significant damage to the conductor 20B.